All hearing aids use similar parts to carry sounds from the environment into your ear and make them louder. Hearing aids vary a great deal in price, size, special features and the way they're placed in your ear.

The following are common hearing aid styles, beginning with the smallest, least visible in the ear. Hearing aid designers keep making smaller hearing aids to meet the demand for a hearing aid that is not very noticeable. But the smaller aids may not have the power to give you the improved hearing you expect.

Uses very small batteries, which have shorter life and can be difficult to handle

Doesn't contain extra features, such as volume control or a directional microphone

Is susceptible to earwax clogging

In the canal

An in-the-canal (ITC) hearing aid is custom molded and fits partly in the ear canal. This style can improve mild to moderate hearing loss in adults.

An in-the-canal hearing aid:

Is less visible in the ear than larger styles

Includes features that won't fit on completely-in-the-canal aids, but may be difficult to adjust due to its small size

Is susceptible to earwax clogging

In the ear

An in-the-ear (ITE) hearing aid is custom made in two styles — one that fills most of the bowl-shaped area of your outer ear (full shell) and one that fills only the lower part (half shell). Both are helpful for people with mild to severe hearing loss.

An in-the-ear hearing aid:

Includes features such as volume control and directional microphones that are easier to adjust

Is generally easier to insert

Uses larger batteries, which are easier to handle and last longer

Is susceptible to earwax clogging

May pick up more wind noise than smaller devices

Is more visible in the ear than smaller devices

Behind the ear

A behind-the-ear (BTE) hearing aid hooks over the top of your ear and rests behind the ear. A tube connects the hearing aid to a custom earpiece called an earmold that fits in your ear canal. This type is appropriate for people of all ages and those with almost any type of hearing loss.

A behind-the-ear hearing aid:

Traditionally has been the largest type of hearing aid, though some newer mini designs are streamlined and barely visible

Is capable of more amplification than are other styles

May pick up more wind noise than other styles

Receiver in canal or receiver in the ear

The receiver-in-canal (RIC) and receiver-in-the-ear (RITE) styles are similar to a behind-the-ear hearing aid with the speaker or receiver in the canal or in the ear. A tiny wire, rather than tubing, connects the pieces.

A receiver-in-canal hearing aid:

Has a less visible behind-the-ear portion

Is susceptible to earwax clogging

Open fit

An open-fit hearing aid is a variation of the behind-the-ear hearing aid. This style keeps the ear canal very open, allowing for low-frequency sounds to enter the ear naturally and for high-frequency sounds to be amplified through the hearing aid. This makes the style a good choice for people with mild to profound hearing loss.

The open-fit behind-the-ear style has become the most popular. An open-fit hearing aid:

Is less visible

Doesn't plug the ear like the small in-the-canal hearing aids do, making your own speech sound better to you

Is difficult to handle due to small parts and batteries

Often lacks manual adjustments due to its small size

Hearing aids make sounds louder so that you can hear them better. Small microphones collect sounds from the environment. A computer chip converts the incoming sound into digital code. Then it analyzes and adjusts the sound based on your hearing loss, listening needs and the level of the sounds around you. The signals are then converted back into sound waves and delivered to your ears through speakers.

Some hearing aid optional features improve your ability to hear in specific situations:

Directional microphones. These are aligned on the hearing aid to provide for improved pick up of sounds coming from in front of you with some reduction of sounds coming from behind or beside you. Some hearing aids are capable of focusing on one direction. Directional microphones can improve your ability to hear when you're in an environment with a lot of background noise.

Telephone adapters (telecoils). These make it easier to hear when talking on a telecoil-compatible telephone. The telecoil eliminates the sounds from your environment and only picks up the sounds from the telephone. Some hearing aids switch automatically when the phone is held up to the hearing aid. And some aids send the phone signal to the other ear so that you can hear the phone in both ears when holding the phone over one hearing aid.

Wireless connectivity. Increasingly, hearing aids can wirelessly interface with certain Bluetooth-compatible devices, such as cellphones, music players and televisions. You may need to use an intermediary device to pick up the phone or other signal and send it to the hearing aid.

Remote controls. Some hearing aids come with a remote control, so you can adjust features without touching the hearing aid.

Direct audio input. This feature allows you to plug in to audio from a television, a computer, a music device and so on.

Variable programming. Some hearing aids can store several preprogrammed settings for various listening needs and environments.

Synchronization. For an individual with two hearing aids, the aids can be programmed to function together so that adjustments made to a hearing aid on one ear (volume control or program changes) will also be made on the other aid, allowing for simpler control.

When looking for a hearing aid, explore your options to understand what type of hearing aid will work best for you. Also:

Get a checkup. See your doctor to rule out correctable causes of hearing loss, such as earwax, an infection and a tumor. And have your hearing tested by a hearing specialist (audiologist).

Seek a referral to a reputable audiologist. If you don't know a good audiologist, ask your doctor for a referral. An audiologist will assess your hearing and help you choose the most appropriate aid and adjust the device to meet your needs. You may get best results with two hearing aids.

Ask about a trial period. You can usually get a hearing aid with a trial period. It may take you a while to get used to the device and decide if it's right for you. Have the seller put in writing the cost of a trial, whether this amount is credited toward the final cost of the hearing aid, and how much is refundable if you return the hearing aid during the trial period.

Think about future needs. Ask whether the hearing aid you've chosen is capable of increased power so that it will still be useful if your hearing loss gets worse.

Check for a warranty. Make sure the hearing aid includes a warranty that covers parts and labor for a specified period.

Plan for the expense. The cost of hearing aids varies widely — from about a thousand dollars to several thousand. Professional fees, remote controls and other hearing aid options may cost extra. Talk to your audiologist about your needs and expectations.

Some private insurance policies cover part or all of the cost of hearing aids — check your policy to be sure. Medicare doesn't cover the cost of hearing aids. In many states, medical assistance covers hearing aids, but sometimes for just one ear. If you're a veteran, you may be able to get your hearing aid at no cost.

Getting used to a hearing aid takes time. You'll likely notice your listening skills improve gradually as you become accustomed to amplification. Even your own voice sounds different when you wear a hearing aid.

Allow time to get used to the hearing aid. It may take several weeks or months before you're used to the hearing aid. But the more you use it, the more quickly you'll adjust to amplified sounds.

Practice using the hearing aid in different environments. Your amplified hearing will sound different in different places. First try using your hearing aid in quiet places.

Seek support and try to stay positive. A willingness to practice and the support of family and friends help determine your success with your new hearing aid. You may also consider joining a support group for people new to hearing aids.

Go back for a follow-up. Most providers include the cost of one follow-up visit in their fee. It's a good idea to take advantage of this for any adjustments and to ensure your new hearing aid is working for you as well as it can.

Your success with hearing aids will be helped by wearing them regularly and taking good care of them. In addition, an audiologist can tell you about new hearing aids and devices that become available and help you make changes to meet your needs. The goal is that, in time, you find a hearing aid you're comfortable with and that enhances your ability to hear and communicate.

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